Influence of type of lining in high-pressure grinding rolls on effectiveness of copper ore comminution

Comminution in a High-Pressure Grinding Rolls (HPGR) device is considered as one of the most efficient method to break particles, in terms of the energy utilization. Two main types of the rolls linings are applied in hard ore grinding: studded and hexagonal, which show varied characteristics of operation and have different lifetime of service. The article concerns the analysis of HPGR device operation for various linings of the rolls. Two pilot-scale test programmes were run and performance of both types of rolls was tested in terms of energy consumption, technological effects measured by means of comminution ratio, lifetime service as well as economic aspects. Results of investigation show, that much longer lifetime service was obtained for the studded rolls, while hexagonal ones are more favourable from economic scope. The feed material for the HPGR comminution tests was Polish copper ore from two divisions of processing plants of KGHM Polska Miedz S.A. Taking into account that industrial comminution operations in mining and mineral processing sector consume over 50% of total energy utilized for ore treatment operations, the problem is of a major significance, especially in terms of optimization of hard ore crushing and grinding circuits.